US3662792A

US3662792A - Anti-overspill container filling apparatus

Info

Publication number: US3662792A
Authority: US
Inventors: Ian James Grant
Original assignee: BP PLC
Current assignee: BP PLC
Priority date: 1969-02-06
Filing date: 1970-02-06
Publication date: 1972-05-16
Anticipated expiration: 1989-05-16
Also published as: CH511766A; CA923472A; NL7001634A; GB1295835A; FR2032776A5; BE745643A; DE2005481A1; DK125816B

Abstract

A pneumatically operated overspill prevention system to close a control valve in a liquid supply line if a liquid level sensor mounted in a container being filled responds to a predetermined liquid level. The system includes a pneumatically extensible member mounted in linkage between the valve and a conventional preset meter with the linkage collapsing and the valve automatically returning to a closed position in the event the sensor detects an excessive liquid level. The entire system is pneumatic and is failsafe in that the valve automatically opens in the event of failure of the compressed air supply of the control assembly.

Description

ANTI-OVERSPILL CONTAINER FILLING APPARATUS,

Inventor: Ian James Grant, Orpington, England The British Petroleum CompanyLirnited, London, England Feb. 6, 1970 Assignee:

Filed:

Appl. No.:

Foreign Application Priority Data Feb. 6, 1969 Great Britain ..6,476/69 US. Cl ..l4l/l98, 137/413 Int. Cl ..B67d 5/04 Field of Search 137/234, 6, 389, 393, 413-415,

References Cited UNITED STATES PATENTS 9/1965 Vergobbi .1 141/41 X 51 May 16, 1972 3,323,560 6/1967 Ehlers ..l41/208 3,516,455 6/1970 Carler Primary Examiner-Edward J. Earls Attorney-Baldwin, Wright, Diller & Brown [57] ABSTRACT A pneumatically operated overspill prevention system to close a control valve in a liquid supply line if a liquid level sensor mounted in a container being filled responds to a predetermined liquid level. The system includes a pneumatically extensible member mounted in linkage between the valve and a conventional preset meter with the linkage collapsing and the valve automatically returning to a closed position in the event the sensor detects an excessive liquid level. The entire system is pneumatic and is failsafe in that the valve automatically opens in the event of failure of the compressed air supply of the control assembly.

13 Claims, 4 Drawing figures 20 METER pezs r DEV/CE Patented May 16, 1972 3,662,792

3 Sheets-Sheet 1 lnventor By M A /20m Attorneys Patented May 16, 1972 3,662,792

3 Sheets-Sheet 2 v Inventor Shaw W y W m5 M Attorneya Patented May 16, 1972 3,662,792

3 Sheets-Sheet 3 ANTI-OVERSPILL CONTAINER FILLING APPARATUS This invention relates to apparatus for preventing the overflow of liquid in the filling of a container.

Spillage of liquid from a container is not only wasteful but when the liquid is flammable may constitute a substantial'fire hazard.

It is a main object of the present inventionto provide apparatus for preventing overflow of liquid during the filling of a container. It is a further object of the present invention to provide apparatus for automatically preventing overflow of liquid, particularly flammable liquid such as petroleum products, in the filling of a container thereby to reduce the fire hazard inherent in such an operation. It is an evenfurther object of the present invention to provide pneumatic apparatus for reducing the fire hazard inherent in the filling of 'a container tag, a tanker vehicle with flammable petroleum products.

Apparatus in accordance with the'present invention comprises-means for sensing or detecting the level of liquid in a container, means for providing a pneumatic signal in dependence on the state of the sensing means, and means responsive to the pneumatic signal provided when the liquid reaches a predetermined level for terminating the supply of liquid to the container.

A preferred embodiment in accordance with the present invention will now be described by way of example with reference to the accompanying schematic drawings in which:

FIG. 1 is a schematic showing of an apparatus for preventing overflow of flammable petroleum products in the filling of a tanker vehicle,

FIG. 2 is a schematic showing of the mechanical linkage of the invention,

FIG. 3 is a schematic showing of a modification of the linkage of FIG. 2,

FIG. 4 is a perspective view of a specific application of the invention.

In one example of the invention, apparatus is arranged such that a change from a positive back pressure pneumatic signal to a negative back pressure pneumatic signal occurs when an overflow condition occurs, and following this change of signal, the means for terminating the supply of liquid is actuated.

The present invention further provides, for use in the apparatus described above, a meter preset device having a pneu matically operated mechanical linkage to control a valve in a liquid supply line.

The following description relates to the filling'of a road or rail tanker vehicle with petroleum products. However it will be appreciated that the apparatus described may be used for preventing overflow of liquid in filling containers with any liquid although it is of particular use with flammable liquid.

Referring to FlG. 1 a series chain 1 of liquid-level sensing units, e.g., detection floats 2, is' mounted within a tanker vehicle, one detection float being mounted per compartment, at or just above the maximum desired liquid level. The chain of detection units, each of which is normally closed, is connected to a conduit 3 mounted on the vehicle for connection to a source of air at low pressure e.g., 4 to inches of water.

The conduit 3 may be coupled by means of an air-connector 4 incorporating an easy-break joint either at the vehicle end as shown in FIG. 1, or at a gantry end (not shown), to a source of low pressure air emanating from conduit 5 provided on the (although a fluid logic circuit may alternatively be employed for example), and thence via conduit 13 to an air cylinder 14 which is mechanically linked between a preset device 20 and a valve'21 located in the pipe line 22 for filling the vehicle.

The types of detection floats are for example, float-operated valves (acting as low pressure back sensors). Alternatively, use may be made of diaphragm-operated valves or of a diptube sensor, the dip-tube valve operating so that the condition of liquid blocking the end of an open tube immersed in the liquid results ina back pressure signal. The application of the invention, for example, to road tanker vehicles or to rail car loading, may decide which detection means is employed.

The preset meter is set for the required gallonage by operating the manually adjustable digital display. When the required gallonage has been dispensed the preset latching mechanism is actuated so that further flow of product through the valve is prevented. However should the liquid overflow the desired liquid level in a compartment for any reason before the indicated gallonage has been dispensed, which may occur for example when the operator sets the digital display for 5,000 gallons when the compartment can hold only 500 gallons, the following occurs. One of the chain 1 of floats 2 is opened so that a pneumatic negative pressure signal is generated in the conduit 3 which actuates the relay 12.

Air at a pressure of 80 p.s.i.g. may be used for example, in the high pressure lines, while air at a pressure of 0.2-0.4 p.s.i.g. may be used in low pressure lines. The use of high pressure ensures that the conduits are kept quite clear.

Instead of using low pressure air, high pressure air may be 7 used in conjunction with a bubbling tube but of course this gantry of the loading bay inwhich the tanker vehicle is located for the filling thereof with petroleum products.

The low pressure air is directed to the conduit 5 from a reducing valve 6 supplied with air at high pressure via a high pressure regulator 7 and a filter 8 from an air supply 9.

The conduit 5 is electrically connected to true earth 10 so that when the conduit 3 is connected to the conduit Sby means of coupling 4 the tanker vehicle is itself connected to true earth. The conduit 3 is mounted on the vehicle and it is earthed'to the vehicle chassis.

Air at high pressure is alsosupplied from the high pressure regulator 7 via branch conduit 11 to a step-up relay 12 could not be employed with a so-called close-filled tank which would not lend itself to the escape of air.

A pneumatic system is inherently safer than an electrical system.

Air valves may be used, as is known, to ensure that it is only when the loading arm is in the correct position e.g., when it is swung into the loading bay and is also lowered, that the system is able to operate. Air valves may be incorporated to ensure that all the valves in the product line, controlling the supply of product to loading arms in use with a vehicle, are closed in the event of an overspill. The product line valves remain closed until the surplus product is removed from a tanker compartment to prevent further loading under hazardous conditions.

Referring to FIG. 2, a mechanical linkage is provided between the manual control arm 16 of a meter preset device 20 and the spring loaded control valve 21 in the product supply line 22. This linkage comprises air cylinder 14 housing a piston 50. The cylinder 14 is connected via a push rod 19 to a lever 17 which directly operates valve 21. The piston is connected via a push rod 51 to the control arm 16. The piston 50 slides within the cylinder 14'and is movable by compressed air supplied at inlet 52 connected to conduit l3. Conduit 13 is connected to the step-up relay or fluid logic 12 which includes a valve arrangement either for pressurizing conduit 13 (during normal filling) or venting conduit 13 to atmosphere (if an overspill condition occurs). A vent 53 to atmosphere is provided'in the cylinder 14 beneath the piston 50.

In operation the piston 50 is moved downwardly under air pressure, line 13 being pressurized because the sensors 2 (of FIG. 1) are closed. Since the cylinder 14 is now pressurized, when the control arm 16 is pulled downwards the

push rods

51 and 19 rise together. Push rod 51 rises when arm 16 moves downwards because of a lever arrangement 60. The lever 17 is thus raised against the bias of a return spring 18 connected to the lever 17 and the valve 21 is opened to allow product to flow.

If a sensor 2 now opens in response to an overspill condition, the step-up relay or fluid logic circuit vents conduit 13 to atmosphere. The piston 50 and cylinder 14 are then free for relative movement and the lever 17 is drawn downwardly by its spring return 18 pulling the cylinder 14 down relative the piston 50; The valve 21 then closes to terminate the product flow in the supply line 22.

if an overfilled tanker is removed after valve 21 has automatically closed due to a sensor 2 opening, and another tanker made ready for filling (its sensors 2 being closed and connected to coupling 4), since the meter preset device is still latched in the valve opening position, product will be dispensed through valve 21 as soon as cylinder 14 is against pressurized, i.e., when coupling 4 is made. In the absence of a safety device on the loading arm, product could then be dispensed without the loading am being located in a compartment of said other tanker. To overcome this problem, the cylinder 14 is modified as shown in FIG. 3.

In FIG. 3 a disc 54 is secured to a connecting rod 55 of the piston 50, and a pilot valve 56 is fixed to the outside of the cylinder 14. A plunger of the pilot valve 56 is actuated by the disc 54 when the piston is at its lowest position, i.e., under pressure from conduit 13. The pilot valve controls the air supply to the cylinder 14 by means of a suitable control valve incorporated in the step-up relay or fluid logic control 12. The plunger of the pilot valve 56 is released when the cylinder 14 is vented to atmosphere because of an overspill condition. Thus, only when the meter preset device 20 has been unlatched by raising the control arm 16, can air be supplied via conduit 13 to pressurize the cylinder 14 to allow valve 21 to be opened.

Provided no sensor 2 responds to an overspill condition, the latching mechanism of the meter preset device 20 trips when the correct volume of product has been supplied, and the control arm 16 rises to lower push rod 51, cylinder 14, push rod 19 and lever 17 to close the valve 21. The piston 50 abuts a stop at the end of the cylinder 14 to allow the

push rods

19 and 51 to move down simultaneously.

Referring to FIG. 4, the meter preset device 20 controls the preset valve 21 in the product line 22. A bulkmeter 23 operates a counter or register 24 on the meter preset device 20. The assembly 40 includes an indentity card reader 25 in which there is a slot 26 for inserting an identity card having information thereon which may be scanned by the reader. Also included in the assembly 40 is a ticket printer 41 incorporating a data logger to record the information from an identity card and the quantity of product dispensed. This information is recorded on ticket or a paper roll.

A product outlet line 27 is connected to a pivotable loading arm 28, the position of the arm 28 being sensed by an arm position sensor 29. The loading arm 28 terminates at at a discharge pipe 30 locatable in a compartment 31 of a road tanker 32. The tanker 32 has a plurality of compartments 31 each provided with overspill detecting or sensing means 33, such as the previously described detection floats 2. The detecting or sensing means 33 are commonly connected to the conduit 3 which is in turn connected to conduit by the air connector 4. Conduit 5 and the arm position sensor 29 are operatively connected to the assembly 40 as shown.

Before an operator loads the tanker 32 to withdraw product he will have to insert a valid identity card. The operation of a ticket printer will record the data on the drivers identity card (e.g., the drivers identity number, the Terminal code number etc.,) and the meter totalizer reading both before and after loading. The meter ticket device may be retained within the box attached to the printer and carry the print out. Altematively the separate meter tickets may be replaced with a continuous roll of paper within the meter head which will record the same information. The data log roll will give information in a more convenient form thereby saving administrative time in sorting and analyzing the meter ticket copies. This is useful in providing data for input to a computer.

Identity cards issued to the drivers are checked on a card reader. This prevents unauthorized withdrawal of product. Interlocks built into the system will ensure that at all times:

a. An authorized driver's identity card is in the reader.

b. The earthing lead has been attached to the vehicle.

0. Vehicle compartments cannot be overfilled to cause an d. The meter ticket has been inserted and the start" gallonage printed.

e. The loading arm has been depressed below the horizontal.

The possibility of including other features (e.g., quantity control cards, additive injection indication etc.) will depend upon the savings such a system might offer. It is possible that the system could be extended to give remote print-outs.

What we claim is:

1. Apparatus for filling a container with a liquid and preventing overflow, said apparatus comprising a liquid supply line having a normally closed control valve therein for controlling the flow of liquid through said supply line, and pressure actuated pneumatic control means for holding said control valve in an open position during a filling operation, said pneumatic control means including liquid level sensor means fixedly mounted in said container operable when the liquid level within said container rises above a predetermined point to render said pneumatic control means inoperative by lowering the pressure level within said pneumatic control means to hold said control valve in a open position, and a releaseable connecting means between said pneumatic control means and other parts of said pressure actuated pneumatic control means for automatically uncoupling said liquid level sensor means upon undue movement of the container relative to said apparatus and for automatically reducing pressure within said pressure actuated control means to close said control valve.

2. The apparatus of claim 1 wherein said pneumatic control means includes a pneumatic actuator, a supply of compressed air, and an air valve controlling the flow of air from said air supply to said actuator, and said liquid level sensor means being connected to said air valve for holding said air valve open only when the liquid level within the container is below a predetermined level.

3. The apparatus of claim 2 wherein said liquid level sensor includes energizing means, and said air valve is open only when said energizing means are activated.

4. The apparatus of claim 2 wherein said air valve has a further compressed air line connected thereto for holding the same in an open position, and said liquid level sensor means are connected to said further air line for controlling pressure therein.

5. The apparatus of claim 4 wherein said further air line is coupled to said compressed air supply for receiving air therefrom.

6. The apparatus of claim 4 wherein said further air line is coupled to said compressed air supply for receiving air therefrom, and a pressure reducing valve between said compressed air supply and said further air line whereby air pressure in said further air line is low as compared to that supplied to said pneumatic actuator.

7. The apparatus of claim 6 wherein said air valve is in the form of a step up relay connected to both said compressed air source and said low pressure air in said further air line.

8. The apparatus of claim 4 wherein said liquid level sensor means are operative to bleed said further air line and reduce air pressure therein when the liquid level in the container reaches a predetermined level.

9. The apparatus of claim 1 wherein pneumatic control means includes a meter preset device having a latching mechanism for latching said control valve in an operative position, linkage between said latching mechanism and said control valve, and said linkage including a pressure extensible pneumatic linkage.

10. Apparatus as claimed in claim 9 in which the pneumatic linkage comprises a cylinder housing a piston, each being connected respectively to one or other of the control arm or valve operating means by a push rod.

11. Apparatus as claimed in claim 10 in which abutment means is attached to a connecting rod of the piston for abutting an actuator of a pilot valve secured to the cylinder, the pilot valve controlling the air supply to the pneumatic linkage such that the preset meter device must be initially unlatched, and then latched, to allow the pneumatic linkage to be pressurized.

and said biasingly closable valve controlling means whereby said valve is biasingly closed.

13. Apparatus as claimed in claim 12 in which the said meter preset device incorporates an identity card reader and associated locking means to enable the operation of the meter preset only when a suitable card is inserted in the identify card reader, and a print-out and logging device for recording information on the identity card and the quantity of liquid dispersed.

l i I l

Claims

3. The apparatus of claim 2 wherein said liquid level sensor includes energizing means, and said air valve is open only when said energizing means are activated. 4. The apparatus of claim 2 wherein said air valve has a further compressed air line connected thereto for holding the same in aN open position, and said liquid level sensor means are connected to said further air line for controlling pressure therein.

12. The apparatus of claim 1 wherein pneumatic control means includes a meter preset device having a latching mechanism for latching said control valve in an operative position, linkage between said latching mechanism and said control valve, and said linkage including an extensible normally pressurized pneumatic linkage joining said control arm to said biasingly closable valve for simultaneous movement thereof to hold open the valve, said pneumatic linkage being decompressible in response to the generation of said pneumatic signal to allow relative movement between said control arm and said biasingly closable valve controlling means whereby said valve is biasingly closed.